Unwinding strand from a traversewound package or the like



1964 R. K..STANLEY 3,145,947

UNWINDING STRAND FROM A TRAVERSE-WOUND PACKAGE OR THE LIKE Filed Aug. 13, 1962 INVENTOR 190554 7 A. SUI/V15) A TTU/PIVEX United States Patent "ice 3,145,947 UNWINDING STRAND FROM A TRAVERSE- WOUND PACKAGE OR THE LIKE Robert K. Stanley, Plymouth Meeting, Pa, assignor to Techniservice Corporation, Philadelphia, Pa., a corporation of Pennsylvania Filed Aug. 13, 1962, Ser. No. 216,447 Claims. (Cl. 242-147) This invention relates to unwinding of textile strands from traverse-wound packages or the like and minimization of tension variations therein, especially macromolecularly orientable strands to be drawn or attenuated to increased length to increase the orientation thereof, or oriented strands to be crimped.

As it is well known, it is diflicult to unwind a strand at constant tension from a traverse-wound package because the length of unwound yarn at the center of the traverse pattern or wind is less than that on either side of the center. At the reversal of the wind, at each end of the package, a tension maximum occurs, while at the center of the wind a tension minimum occurs. It is not usually practicable to vary the rotational speed of the package to compensate for these variations, and conventional compensating devices, such as Weighted or springbiased arms or guides, introduce additional variations while possibly smoothing out the extremes mentioned. Unevenly drawn and, at least in some instances, unevenly crimped textile strands exhibit, when subsequently dyed, undesirable irregularities of dye take-up, manifested as variations in color or shade.

A primary object of the present invention is minimization of tension variations in textile strand being unwound from a traverse-wound package.

An object is presentation of orientable textile strand to a drawing system at essentially uniform tension.

Another object is elimination of relatively undrawn portions from textile strands unwound from traverse-wound packages.

An object is improved preparation of textile strands for uniform dyeability.

A further object is improved crimping of textile strands unwound from a traverse-wound package.

Other objects of this invention, together with means and methods of attaining the various objects, will be apparent from the following description and the accompanying drawings.

FIG. 1 is a side elevation of apparatus useful according to this invention.

FIG. 2 is a front elevation of strand-unwinding components, of the same apparatus, taken at IIII of FIG. 1;

FIG. 3 is a perspective view of strand-drawing components of the same apparatus; and

FIG. 4 is a front elevation, partly in section, of strandcrirnping components of the same apparatus taken at IVIV of FIG. 1.

In general, the objects of the present invention are ac complished, in the unwinding of a strand along a path from a source of supply to a use or windup location, by pulling the strand away from the source and passing it through a succession of alternating straight and curved portions of the path, each interconnecting curved portion having a fixed axis about which it curves, there being a plurality of the interconnecting curved portions freely movable along their axes, whereupon the adjacent straight portions are shiftable laterally and variable in length.

In an apparatus embodiment, the invention provides means for pulling a textile strand from an unreeling traverse-wound package over a plurality of rolls mounted for rotation on axes paralleling the package axis and through a friction-free guide at an intermediate position 3,145,947 Patented Aug. 25, 1964 with respect to the package ends, the strand describing an angle of at least about a quarter circle between leaving the package and the guide and being free to move axially along the rolls between the package and guide. The invention contemplates a continuous unwinding of textile strand, as above, and drawing or crimping (or both) of the strand.

FIG. 1 shows, in side elevation, apparatus useful according to this invention. Subsequent views show various portions of the same apparatus in front elevation. In all views the showing is relatively diagrammatic or schematic, in that the associated supporting and driving apparatus and related parts, which are of conventional design and construction, are omitted in the interest of clarity.

Package 11 of textile strand, from which strand 10 is shown as unreeling, is mounted for rotation on axle 12 suitably supported. Mounted on axes parallel thereto are roll 13 located above and behind (v. FIG. 2) the package, roll 14 located below and behind the package, and roller guide 15 located ahead of and below the pack age and centered from end to end thereof.

The components shown in FIG. 3 as well as in FIG. 1 comprise a strand-drawing system and include first pair of rolls 21, 22 and second pair of rolls 24, 25, together with fixed draw pin 23 located between the two pairs of rolls. At least one roll (preferably both) in each pair of rolls is driven, and the surface speed of the second pair is greater than that of the first pair so that strand travelling through the system is extended by contact therewith. The strand is shown as making at least a complete wrap around rolls 21, 22 as a set, a turn about the draw pin, and then a wrap or more around rolls 24, 25 as a set. The ratio of suitable surface speeds depends upon the degree of macromolecular orientation of the incoming strand and the composition of the strand; as an example, a ratio of about four to one (a 4 draw) is often employed for strands of polyamide, such as 66 nylon.

The components shown in FIG. 4 as well as in FIG. 1 comprise a crimping system including specifically a stuffer-crimper, of which the major components are a pair of stufling rolls 31, 32 and a stufiing chamber 33, which has a longitudinal bore therethrough and has pivoted cap 34 at the top or opposite end from the rolls. Strand 10 entering the nip of the rolls is stuffed into the chamber, from which its exit is impeded by the cap (which may be weighted or spring-biased) and thereby crimped as its entrance into the chamber is impeded by the accumulation of strand therein. Part of the front wall of chamber 33 is cut away in FIG. 4 to reveal a portion of the strand accumulation therein (shown rather stylized, for clarity). Strand 10 expelled in crimped form from the top of the chamber is shown as being wound up under relatively relaxed condition onto bobbin or similar package 35 driven by contact with drive roll 36.

The drawing and crimping systems and components shown in FIGS. 3 and 4, as well as in FIG. 1, are conventional as such, and the present invention is directed particularly to the preceding portion of FIG. 1 as such and in combination with one or more of those other systems and components.

It will be apparent that as strand 10 is unreeled from package 11 the locus of departure of the strand from the package reciprocates from end to end of the package, as suggested in FIG. 2 by the solid line (representing strand 1t) unreeling from the midportion of the package) and the unlike broken lines (representing the extreme positions of the traverse-wound strand) at the extreme left and right top edges of the package. Intermediate positions may be readily visualized but are omitted from the view in the interest of clarity.

Roller guide 15, which is flanged like a pulley, is rotatable but is located at a relatively fixed position along its axis, being centered from end to end of strand package 11. As the strand unreels from the package and about rolls 13, 14 and the roller guide, the strand traverses the successive rolls to a successively decreasing extent as compared with the full traverse thereof on the package itself. FIG. 4 shows that the resistance offered by each roll to the strand results in a difierence between the angle at which the strand first contacts the roll and the angle at which it leaves the roll. Even at the straight-ahead or midtraverse position, the strand (although not so shown because to do so might render the operation less evident) usually will occupy somewhat different positions on the rolls because of time lag in movement of the strand therealong.

The eifect of this arrangement whereby the strand traverses to a reduced extent a plurality of rolls located as shown smoothes out the tension changes characteristic of a strand unreeled from a traverse-wound package. The strand should come into suflicient contact with each roll to affect the course of the strand therealong, as distinguished from a minor degree of contact that merely deflects the strand from a straight-line path. In general it is desirable that the strand pass through at least (in total) a right angle of are from leaving the package until encountering the roller guide. No practical advantage attends operation with any more than a full circle of such are, and the preferred angle is generally about midway between such maximum and the mentioned minimum.

It is apparent from FIGS. 1 and 2 that the rolls l3 and 14 are on axes parallel to one another and to the axis of strand package it; it is also apparent from FIG. 1 that the three axes, when viewed end-on, form the corners of a triangle. Such arrangement is conducive to the desired movement of the strand back and forth along the roll surfaces. Of course, more than two rolls may be used, arranged so that their axes and that of the package, when viewed end-on, are located at the corners of a polygon other than a triangle. The arrangement should be such that the minimum contact angle per roll is about one hundred degree of are divided by the number of such rolls.

The pulling force to unreel the strand may be furnished by the rolls of the drawing system or, in the event of the unreeling of an already drawn strand to be crimped, by one or more rolls in or associated with the crimper itself. The rolls corresponding to illustrated rolls 13 and 14 need not be driven, although they may be (especially if massive) at a rate compatible with that of subsequent rolls. The package normally will be braked slightly, and the roller guide will be completely free running.

The present invention is beneficial in eliminating ten sion variations in strand presented to a drawing system or a crimping system (or both). Strand so treated, when subsequently dyed, is free from objectionable irregularities characteristic of uneven drawing (or crimping). Additional advantages will be recognized by and accrue to those who practice this invention, which although described by way of example above is defined and circum scribed only by the following claims.

I claim:

1. In the unwinding and forwarding of a strand along a path from a source of supply to a use or windup location, the improvement comprising pulling the strand away from the source and passing it through a succession of alternating straight and curved portions of the path, each interconnecting curved portion having a fixed axis about which it curves, there being a plurality of the interconnecting curved portions freely movable along their axes, whereupon the adjacent straight portions are shiftable laterally and variable in length.

2. In the unwinding and forwarding of a strand along a path from a source of supply to a use or windup location, the improvement comprising pulling the strand away from the source and passing it through a succession of alternating straight and curved portions of the path, each adjacent pair of straight portions being interconnected by a curved portion, each interconnecting curved portion having a fixed axis about which it curves, there being a plurality of the interconnecting curved portions readily movable along their axes, whereupon the adjacent straight portions are shiftable laterally and variable in length, all the movable curved portions curving in the same direction.

3. In the unwinding and forwarding of a strand along a path from a source of supply to a use or windup location, the improvement comprising pulling the strand away from the source and passing it through a succes sion of alternating straight and curved portions of the path, including a final straight portion leading to the use or windup location, each adjacent pair of straight portions being interconnected by a curved portion, each interconnecting curved portion having a fixed axis about which it curves, the curved portion immediately preceding the final straight portion occupying a fixed location along its axis, there being a plurality of the curved portions freely movable along their axes within a limited range, whereupon the adjacent straight portions are shiftable laterally and variable in length.

4. In the unwinding and forwarding of a strand along a path from a source of supply to a use or windup location, the improvement comprising pulling the strand away from the source and passing it through a succession of alternating straight and curved portions of the path, including a final straight portion leading to the use or windup location, each adjacent pair of straight portions being interconnected by a curved portion, each interconnecting curved portion having a fixed axis about which it curves, the curved portion immediately preceding the final straight portion occupying a fixed location along its axis, there being a plurality of preceding curved portions each of which is curved through less than a semicircle of are about its axis and is readily movable along its axis within a limited range, whereupon the adjacent straight portions are shiftable laterally and variable in length, the total curvature of the curved portions about their axes, all of which are parallel, being at least a quarter circle of arc and at most about a circle.

5. In the unwinding and forwarding of a strand along a path from a source of supply to a use or windup location, the improvement comprising minimizing tension variations in the strand by the steps of pulling the strand away from the source and passing it through a succession of alternating straight and curved portions of the path, including a final straight portion leading to the use or windup location, each adjacent pair of straight portions being interconnected by a curved portion, each interconnecting curved portion having a fixed straight axis about which it curves, the curved portion immediately preceding the final straight portion occupying a fixed location along its axis, all the preceding curved portions curving in the same rotational direction through a total arc of at least about a quarter circle and at most about a circle, each curving through an angle of about lO0/N where N is the number of such curved portions, and being movable along their axes within a limited range under constraint imposed only by pulling of the strand, whereupon the adjacent straight portions are shiftable laterally and variable in length.

6. Process of strand treatment consisting of pulling a textile strand from an unreeling traverse-wound package over and in contact with a plurality of rolls, all of which are mounted for rotation on fixed axes paralleling the package axis, and then through a friction-free guide located at an intermediate position with respect to the package ends, the strand describing an angle of at least about a quarter circle between leaving the package and the guide and being free to move axially along the rolls between the package and the guide.

7. Apparatus for strand treatment comprising means for supporting a traverse-wound package of textile strand for unreeling, a plurality of rolls mounted rotatably on fixed axes paralleling the package axis, the package axis and roll axes denoting, when viewed end-on, the corners of a polygon, and a roller guide at a fixed location.

8. Apparatus for strand treatment comprising means for supporting a traverse-wound package of textile strand for unreeling, a pair of idler rolls mounted rotatably on axes paralleling the package axis, the package axis and the roll axes denoting, when viewed end-on, the corners of a triangle, and a parallel roller guide at a fixed location centered with respect to the ends of the package and outside the triangle.

9. In apparatus for unwinding and forwarding a strand from a source of supply to a use or windup location, the improvement comprising means for pulling the strand away from the source, a plurality of intervening parallel rolls, all the ll'OllS being mounted for free rotation on fixed axes, and a substantially friction-free yarn guide mounted on a fixed axis and at a fixed location therealong intervening in the yarn path between the rolls and the use or windup location.

References Cited in the file of this patent UNITED STATES PATENTS 920,185 Nursbaumer May 4, 1909 2,289,232 Babcock July 7, 1942 2,346,917 Heger Apr. 18, 1944 2,686,339 Holt Aug. 17, 1954 2,733,122 Herele et a1. Jan. 31, 1956 

1. IN THE UNWINDING AND FORWARDING OF A STRAND ALONG A PATH FROM A SOURCE OF SUPPLY TO A USE OR WINDUP LOCATION, THE IMPROVEMENT COMPRISING PULLING THE STRAND AWAY FROM THE SOURCE AND PASSING IT THROUGH A SUCCESSION OF ALTERNATING STRAIGHT AND CURVED PORTIONS OF THE PATH, EACH INTERCONNECTING CURVED PORTION HAVING A FIXED AXIS ABOUT WHICH IT CURVES, THERE BEING A PLURALITY OF THE INTERCONNECTING CURVED PORTIONS FREELY MOVABLE ALONG THEIR AXES, WHEREUPON THE ADJACENT STRAIGHT PORTIONS ARE SHIFTABLE LATERALLY AND VARIABLE IN LENGTH. 